The existing asphalt concrete compositions being used for paving and coating asphalt concrete roads, airfield runways, various asphalt concrete areas (such as storages, hangars, etc.) do not meet the necessary quality requirements. Environmental effects cause oxidation (aging) and loss of plasticity resulting in initiation of cracks and then in destruction of the pavement.
Studies in this field have been concentrated on optimizing the compositions now in use in an endeavor to obtain satisfactory protection from oxidation and mechanical wear.
Many compositions including various additives have been proposed (in particular, the compositions covered by U.S. Pat. No. 3,846,362 of 1974, US Cl. 524/66; U.S. Pat. No. 4,175,978 of 1979, US Cl. 524/68; U.S. Pat. No. 4,305,855 of 1981, US Cl. 524/62; U.S. Pat. No. 4,403,067 of 1983, US Cl. 524/71; U.S. Pat. No. 4,547,225 of 1985, US Cl. 524/71; and Japanese Patent No. 31341 of 1991).
However, the said compositions did not find wide application for coating the above mentioned areas because of poor quality results.
A later U.S. Pat. (No. 4,737,538 of 1988, US Cl. 524/71,. Int. Cl. C08L95/00) covers polymeric concrete compositions used for molding solids. The compositions contain thermosetting resin and a rubber component.
The cross-bond resins now in use are important for production of rigid solids (objects) but they are unsuitable as specific coatings of motor roads, airfield runways and other similar areas requiring essential flexibility and elasticity of coating compositions.
An important achievement in this field was the invention by Yuri Margulis and Avraham Lavy according to Israeli Patent No. 92917 of 1990, Int. Cl. C08L95/00, and analogous U.S. Pat. No. 5,284,887 published in 1994, US Cl. 524/71, 524/69, 524/68, 524/62, Int. Cl. C08L95/00 (the same inventors).
The compositions according to this invention are finding wider and wider practical use as a top protection layer applied to the asphalt concrete or similar underlying layer of motor roads, airfield runways and similar areas.
The layer of composition applied to the existing asphalt concrete surface penetrates the surface (underlying layer) to a depth of several millimeters, with penetration intensity gradually reducing with depth.
The obtained protection layer increases mechanical stability, reduces oxidation, resists to water penetration and imparts certain elasticity to the coating. The surface layer is resistant to ultraviolet radiation for a long time, and this property reduces aging and erosion of the surface.
Main components of the composition (percentages by weight):
Monomer or monomer mixture chosen from10 to 25methyl methacrylate, acrylate, styreneBitumen 75/2515 to 25Comminuted mineral filler (milled marble,50 to 80limestone, granite, dolomite, talc)Ultraviolet radiation protecting and0.1 to 0.8stabilizing agent (comminuted fly ash ofabout 300 mesh)
An advantageous additive is oleic acid (1 to 3%) or dibutyl phthalate (as plasticizer).
As the composition is applied to a chosen surface, the monomer (or monomer mixture) polymerizes within a relatively short period of time, so that no curing agent is required.
The composition, in addition to its protective action, rejuvenates the aged asphalt concrete surface.
Quite recently methods and means have been found for essential improvement of properties of the above described composition (according to Israeli Patent No. 92917, U.S. Pat. No. 5,284,887 and their analogues) in compliance with the following new objectives:                widening the field of application (in particular, using the composition as a paint not freezing below −40° C., and also for protection of the surfaces of various constructions and structures made of concrete, asphalt concrete, metal, wood);        metal protection from corrosion;        acceleration and a greater depth of rejuvenation of asphalt concrete coatings applied to various constructions and structures;        the use of any type of blown bitumen, and not only bitumen 75/25.        